Increases in atmospheric carbon dioxide (CO2) lead to ocean acidification (OA) which has been shown to alter olfactory behaviours in marine organisms. However, coastal regions experience CO2 levels greater than end-of-century open ocean predictions. I investigated the effects of OA on the olfactory system of the intertidal yellow shore crab, Hemigrapsus oregonensis. I hypothesized that given their variable natural environment these crabs are more tolerant to OA. Crabs demonstrated impaired olfactory behaviour after acute and long-term static exposures to OA. This impairment was correlated with a decrease in olfactory receptor protein expression and a 20% decrease in olfactory sensory neuron volume. Crabs exposed to fluctuating CO2 had intermediate behavioural responses and showed no changes in receptor expression. These results show that coastal crabs are affected by ocean acidification despite their variable natural environment, being particularly vulnerable during upwelling events and this impairment will likely worsen in the future.
Khodikian E., 2024. The effects of ocean acidification on the olfactory system of the yellow shore crab, Hemigrapsus oregonensis. MSc thesis, University of Toronto, 49 p. Thesis.
